BOGOR, Indonesia— The idea of paying people in developing tropical countries to protect their forests, generating carbon credits, and selling them on an international carbon market, gained prominence at the 2007 UN climate change summit in Bali.

In the ensuing years, some 300 initiatives related to this idea, known as REDD+ (Reducing Emissions from Deforestation and forest Degradation) arose in tropical forest countries around the globe. Yet they remain lodged in the preliminary phases.

“The world is at a crossroads where REDD+ has opened up an opportunity for forest conservation, leveraged by global concern about climate change,” the authors write. “But as this book illustrates well, REDD+ faces a steep uphill climb in reaching its objectives.”